The latent dedifferentiation capacity of newt limb muscles is unleashed by a combination of metamorphosis and body growth.

Newts can regenerate their limbs throughout their life-span. Focusing on muscle, certain species of newts such as Cynops pyrrhogaster dedifferentiate muscle fibers in the limb stump and mobilize them for muscle creation in the regenerating limb, as they grow beyond metamorphosis. However, which developmental process is essential for muscle dedifferentiation, metamorphosis or body growth, is unknown.

A developmentally regulated switch from stem cells to dedifferentiation for limb muscle regeneration in newts.

The newt, a urodele amphibian, is able to repeatedly regenerate its limbs throughout its lifespan, whereas other amphibians deteriorate or lose their ability to regenerate limbs after metamorphosis. It remains to be determined whether such an exceptional ability of the newt is either attributed to a strategy, which controls regeneration in larvae, or on a novel one invented by the newt after metamorphosis. Here we report that the newt switches the cellular mechanism for limb regeneration from a stem/progenitor-based mechanism (larval mode) to a dedifferentiation-based one (adult mode) as it transits beyond metamorphosis.

[Isolation and identification of Suavissimoside R1 from roots of Rubus parvifollus used for protecting dopaminergic neurons against MPP+ toxicity].

Objective: Suavissimoside R1 was isolated and identified as an active ingredient from Roots of Rubus parvifollus L, which exhibited protective effect on dopaminergic neurons against MPP+ toxicity.

Methods: The protective effects of crude extracts were investigated after mice were treated with 1-methyl4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). According to the protective effects of crude extracts, suavissimoside R1, one kind of triterpenoid saponin, was separated.